A programmable logic controller (PLC) is a specialized computer control system configured to execute software which continuously gathers data on the state of input devices to control the state of output devices. A PLC typically includes three major components: a processor (which may include volatile memory), volatile memory comprising an application program, and one or more input/output (I/O) ports for connecting to other devices in the automation system.
PLCs are utilized in various industrial settings to control production devices and other automation devices which generate a large amount of data in their daily operations. This data may include, for example, sensor data, actuator and control program parameters, and information associated with service activities. However, conventional automation systems, and conventional PLCs in particular, are not capable of fully utilizing this data. For example, in most systems, due to hardware and software limitations, only a small fraction of this data can be analyzed and stored. Massive amounts of irrelevant data may be produced while important data points are missed. Compression may be applied at the higher automation layers on unimportant data, while important data is lost while travelling through the automation layers. Moreover, even where there are attempts to avoid the loss of data, there may be significant demands placed on the rest of the computing infrastructure. For example, the PLC data processing may result in a high demand on the network bandwidth as well as storage capacity. Additionally, the context of data may be lost while data passes through automation system layers. This causes several undesired secondary effects on the automation system. For example, if data analytics are performed at higher automation layers based on low quality/fidelity data, important data may be lost causing the automation system to operate inefficiently or sub-optimally.
Recent advances in control layer devices have addressed some of the inefficiencies of the system by providing enhanced storage and processing capabilities within the device. However, the capabilities are generally underutilized in conventional systems which force the control layer device to fit within the paradigm of the multi-layer architecture discussed above. Accordingly it is desired to modify the conventional multi-layer architecture in a manner that leverages the collective computing capability of modern PLCs.